1974 D100 frame off build up

Looks like a rattle can job (and not a very good one), you might find that a few cans of brake clean will take it off.
Definitely not rattle can, looks more like Wagner sprayer quality. The crap was absolutely everywhere, radiator hoses included when I first got it. And it's caked on thick! Starts to melt when I'm wire wheeling it. Brake clean hasn't worked, I've tried haha